Eslint: use hermes-eslint parser (experimental)

.eslintignore

@@ -4,7 +4,6 @@
 node_modules/
 
 src/babel-preset-adeira/src/__tests__/__fixtures__
-src/sx-tailwind-website/__github__/flow-typed
 
 # https://github.com/prettier/prettier/issues/6102
 **/__generated__/*.graphql.js

.eslintrc.js

@@ -9,12 +9,10 @@ module.exports = {
     jest: true,
     node: true,
   },
-  parser: '@babel/eslint-parser', // TODO: consider moving this into `eslint-config-adeira`
+  parser: 'hermes-eslint',
   parserOptions: {
+    // https://github.com/facebook/hermes/blob/main/tools/hermes-parser/js/hermes-eslint/README.md
     sourceType: 'module',
-    ecmaVersion: 2021,
-    ecmaFeatures: {
-      jsx: false,
-    },
+    fbt: true,
   },
 };

package.json

@@ -14,13 +14,13 @@
     "@adeira/monorepo-utils": "^0.11.0",
     "@babel/cli": "^7.18.6",
     "@babel/core": "^7.18.6",
-    "@babel/eslint-parser": "^7.18.2",
     "babel-jest": "^28.1.3",
     "babel-loader": "^8.2.5",
     "eslint": "^8.19.0",
     "eslint-formatter-codeframe": "^7.32.1",
     "flow-bin": "^0.182.0",
     "glob": "^8.0.3",
+    "hermes-eslint": "^0.9.0",
     "jest": "^28.1.3",
     "jest-environment-jsdom": "^28.1.3",
     "prettier": "^2.7.1"

src/eslint-config-adeira/CHANGELOG.md

@@ -1,5 +1,13 @@
 # Unreleased
 
+The Eslint Config now requires [`hermes-eslint`](https://www.npmjs.com/package/hermes-eslint) as an Eslint parser. Technically, the config works with any other parser (say `@babel/eslint-parser`) as well, however, some rules were adjusted for `hermes-eslint`. Notably:
+
+- `no-undef` was turned off (not needed, especially in combination with Flow - superfluous rule)
+- `ft-flow/define-flow-type` turned off (not needed with Hermes)
+- `ft-flow/use-flow-type` turned off (not needed with Hermes)
+- `react/jsx-uses-react` turned off (not needed with Hermes)
+- `react/jsx-uses-vars` turned off (not needed with Hermes)
+
 # 7.7.0
 
 - New rule [`@next/next/no-styled-jsx-in-document`](https://nextjs.org/docs/messages/no-styled-jsx-in-document) enabled.

src/eslint-config-adeira/README.md

@@ -1,4 +1,4 @@
-Purpose of this package is to share common eslint configuration among other JS projects. It should not be annoying but rather helpful when you understand _"why"_ of each rule (please give us feedback if you disagree with some rules).
+Eslint config designed to work well for [Adeira](https://github.com/adeira) projects. It's especially powerful in combination with [Flow](https://flow.org/) and [`hermes-eslint`](https://www.npmjs.com/package/hermes-eslint).
 
 # Usage
 
@@ -7,7 +7,7 @@ Before you start you should **remove all Eslint plugins and Prettier** from your
 Install this package (as well as Eslint):
 
 ```
-yarn add eslint @adeira/eslint-config --dev [--ignore-workspace-root-check]
+yarn add eslint @adeira/eslint-config --dev
 ```
 
 And use it in your `.eslintrc.js`:
@@ -24,9 +24,9 @@ module.exports = {
 };
 ```
 
-Strict version of the config turns _some_ warnings into errors. We use warnings as a migration strategy for the future breaking release but you can make the config more strict even today (so your CI will fail). Not all warnings are turned into errors - only the ones considered to be errors in the future version. Please be aware that strict mode is like living on the edge: minor upgrade can break your CI (while others will get only warnings). You will be ready for the future major version though.
+Strict version of the config turns _some_ warnings into errors. We use warnings as a migration strategy for the future breaking release, however, you can make the config more strict even today (so your CI will fail). Not all warnings are turned into errors - only the ones considered to be errors in the future version. Please be aware that strict mode is like living on the edge: minor upgrade can break your CI (while others will get only warnings). You will be ready for the future major version though.
 
-You can also set your eslint as needed with `@babel/eslint-parser` parser for example (you need to install it separately):
+It's recommended using `hermes-eslint` parser with this config (you need to install it separately):
 
 ```js
 const OFF = 0;
@@ -38,13 +38,9 @@ module.exports = {
 
   extends: ['@adeira/eslint-config/strict'],
 
-  parser: '@babel/eslint-parser',
+  parser: 'hermes-eslint',
   parserOptions: {
     sourceType: 'module',
-    ecmaVersion: 2021,
-    ecmaFeatures: {
-      jsx: false,
-    },
   },
 
   env: {
@@ -55,9 +51,7 @@ module.exports = {
 };
 ```
 
-It is important to report any issues with the eslint configuration back so we can improve it **for everyone**. These rules should be related only to how we write JS code so it's perfectly fine if you have some additional rules closely related to your project (`no-restricted-imports` for example).
-
-Also please note that **you should not ignore Eslint warnings**! These warnings are helping you to migrate to the future major version. Some of them will turn into errors in the next major version bump.
+Please note that **you should not ignore Eslint warnings**! These warnings are helping you to migrate to the future major version. Some of them will turn into errors in the next major version bump.
 
 # Config subsets
 

src/eslint-config-adeira/__tests__/__fixtures__/valid-eslint-examples/flow/enums.js

@@ -6,6 +6,7 @@ enum StatusDefault1 {
   Off,
 }
 
+// eslint-disable-next-line no-unused-vars
 enum StatusDefault2 of string {
   Active,
   Paused,
@@ -18,6 +19,7 @@ enum StatusString1 {
   Off = 'off',
 }
 
+// eslint-disable-next-line no-unused-vars
 enum StatusString2 of string {
   Active = 'active',
   Paused = 'paused',
@@ -30,12 +32,14 @@ enum StatusNumber1 {
   Off = 3,
 }
 
+// eslint-disable-next-line no-unused-vars
 enum StatusNumber2 of number {
   Active = 1,
   Paused = 2,
   Off = 3,
 }
 
+// eslint-disable-next-line no-unused-vars
 enum StatusBoolean1 {
   Active = true,
   Off = false,

src/eslint-config-adeira/__tests__/__snapshots__/index.test.js.snap

@@ -200,7 +200,7 @@ Object {
       1,
       "boolean",
     ],
-    "ft-flow/define-flow-type": 1,
+    "ft-flow/define-flow-type": 0,
     "ft-flow/delimiter-dangle": 0,
     "ft-flow/enforce-line-break": 0,
     "ft-flow/enforce-suppression-code": 2,
@@ -265,7 +265,7 @@ Object {
     "ft-flow/type-id-match": 0,
     "ft-flow/type-import-style": 0,
     "ft-flow/union-intersection-spacing": 0,
-    "ft-flow/use-flow-type": 1,
+    "ft-flow/use-flow-type": 0,
     "ft-flow/use-read-only-spread": 2,
     "ft-flow/valid-syntax": 0,
     "func-call-spacing": "off",
@@ -719,7 +719,7 @@ Object {
     "no-this-before-super": 2,
     "no-throw-literal": 1,
     "no-trailing-spaces": "off",
-    "no-undef": 2,
+    "no-undef": 0,
     "no-undef-init": 2,
     "no-undefined": 0,
     "no-underscore-dangle": 0,
@@ -915,8 +915,8 @@ Object {
     "react/jsx-sort-props": 0,
     "react/jsx-space-before-closing": "off",
     "react/jsx-tag-spacing": "off",
-    "react/jsx-uses-react": 1,
-    "react/jsx-uses-vars": 2,
+    "react/jsx-uses-react": 0,
+    "react/jsx-uses-vars": 0,
     "react/jsx-wrap-multilines": "off",
     "react/no-access-state-in-setstate": 2,
     "react/no-adjacent-inline-elements": 0,

src/eslint-config-adeira/__tests__/__snapshots__/presets.test.js.snap

@@ -404,7 +404,7 @@ Object {
     "no-ternary": 0,
     "no-this-before-super": 2,
     "no-throw-literal": 1,
-    "no-undef": 2,
+    "no-undef": 0,
     "no-undef-init": 2,
     "no-undefined": 0,
     "no-underscore-dangle": 0,
@@ -616,7 +616,7 @@ Object {
       1,
       "boolean",
     ],
-    "ft-flow/define-flow-type": 1,
+    "ft-flow/define-flow-type": 0,
     "ft-flow/delimiter-dangle": 0,
     "ft-flow/enforce-line-break": 0,
     "ft-flow/enforce-suppression-code": 2,
@@ -681,7 +681,7 @@ Object {
     "ft-flow/type-id-match": 0,
     "ft-flow/type-import-style": 0,
     "ft-flow/union-intersection-spacing": 0,
-    "ft-flow/use-flow-type": 1,
+    "ft-flow/use-flow-type": 0,
     "ft-flow/use-read-only-spread": 2,
     "ft-flow/valid-syntax": 0,
     "prettier/prettier": Array [
@@ -1050,8 +1050,8 @@ Object {
     "react/jsx-props-no-spreading": 0,
     "react/jsx-sort-default-props": 0,
     "react/jsx-sort-props": 0,
-    "react/jsx-uses-react": 1,
-    "react/jsx-uses-vars": 2,
+    "react/jsx-uses-react": 0,
+    "react/jsx-uses-vars": 0,
     "react/no-access-state-in-setstate": 2,
     "react/no-adjacent-inline-elements": 0,
     "react/no-array-index-key": 0,

src/eslint-config-adeira/src/presets/base.js

@@ -157,7 +157,7 @@ module.exports = ({
     'no-restricted-globals': OFF,
     'no-shadow': OFF,
     'no-shadow-restricted-names': ERROR,
-    'no-undef': ERROR,
+    'no-undef': OFF, // not needed with Flow and `hermes-eslint` parser (superfluous rule)
     'no-undef-init': ERROR,
     'no-undefined': OFF,
     'no-unused-vars': [

src/eslint-config-adeira/src/presets/flowtype.js

@@ -18,7 +18,7 @@ module.exports = ({
     'ft-flow/array-style-simple-type': OFF,
     'ft-flow/arrow-parens': OFF,
     'ft-flow/boolean-style': [NEXT_VERSION_ERROR, 'boolean'],
-    'ft-flow/define-flow-type': WARN,
+    'ft-flow/define-flow-type': OFF, // not needed with `hermes-eslint` parser
     'ft-flow/delimiter-dangle': OFF,
     'ft-flow/enforce-line-break': OFF,
     'ft-flow/enforce-suppression-code': ERROR,
@@ -73,7 +73,7 @@ module.exports = ({
     'ft-flow/type-id-match': OFF,
     'ft-flow/type-import-style': OFF,
     'ft-flow/union-intersection-spacing': OFF,
-    'ft-flow/use-flow-type': WARN,
+    'ft-flow/use-flow-type': OFF, // not needed with `hermes-eslint` parser
     'ft-flow/use-read-only-spread': ERROR,
     'ft-flow/valid-syntax': OFF,
 

src/eslint-config-adeira/src/presets/react.js

@@ -1,6 +1,6 @@
 // @flow
 
-const { ERROR, OFF, WARN, NEXT_VERSION_ERROR } = require('../constants');
+const { ERROR, OFF, NEXT_VERSION_ERROR } = require('../constants');
 const detectReactVersion = require('../detectReactVersion');
 
 /*::
@@ -76,8 +76,8 @@ module.exports = ({
     'react/jsx-props-no-spreading': OFF,
     'react/jsx-sort-default-props': OFF,
     'react/jsx-sort-props': OFF,
-    'react/jsx-uses-react': WARN,
-    'react/jsx-uses-vars': ERROR,
+    'react/jsx-uses-react': OFF, // not needed with `hermes-eslint` parser
+    'react/jsx-uses-vars': OFF, // not needed with `hermes-eslint` parser
     'react/no-access-state-in-setstate': ERROR,
     'react/no-array-index-key': OFF,
     'react/no-arrow-function-lifecycle': ERROR,

src/eslint-fixtures-tester/package.json

@@ -15,9 +15,9 @@
   "dependencies": {
     "@adeira/flow-types-eslint": "0.0.0",
     "@adeira/js": "^2.1.1",
-    "@babel/eslint-parser": "^7.18.2",
     "@babel/runtime": "^7.18.6",
     "eslint": "^8.19.0",
+    "hermes-eslint": "^0.9.0",
     "jest-docblock": "^28.1.1"
   },
   "peerDependencies": {

src/eslint-fixtures-tester/src/index.js

@@ -80,7 +80,7 @@ export default function testFixtures({
   }
 
   const ruleTester = new RuleTester({
-    parser: require.resolve('@babel/eslint-parser'),
+    parser: require.resolve('hermes-eslint'),
   });
 
   ruleTester.run('no-unused-stylesheet', rule, {

src/eslint-plugin-adeira/package.json

@@ -20,8 +20,8 @@
   "devDependencies": {
     "@adeira/eslint-fixtures-tester": "0.1.0",
     "@adeira/flow-types-eslint": "0.0.0",
-    "@babel/eslint-parser": "^7.18.2",
-    "eslint": "^8.19.0"
+    "eslint": "^8.19.0",
+    "hermes-eslint": "^0.9.0"
   },
   "peerDependencies": {
     "graphql": "^14.0.0 || ^15.0.0 || ^16.0.0"

src/eslint-plugin-adeira/src/rules/__tests__/graphql-require-object-description.test.js

@@ -5,7 +5,7 @@ const RuleTester = require('eslint').RuleTester;
 const rule = require('../graphql-require-object-description');
 
 const ruleTester = new RuleTester({
-  parser: require.resolve('@babel/eslint-parser'),
+  parser: require.resolve('hermes-eslint'),
 });
 
 ruleTester.run('graphql-require-object-description', rule, {

src/eslint-plugin-adeira/src/rules/__tests__/no-duplicate-import-type-import.test.js

@@ -5,7 +5,7 @@ const RuleTester = require('eslint').RuleTester;
 const rule = require('../no-duplicate-import-type-import');
 
 const ruleTester = new RuleTester({
-  parser: require.resolve('@babel/eslint-parser'),
+  parser: require.resolve('hermes-eslint'),
 });
 
 ruleTester.run('no-duplicate-import', rule, {

src/eslint-plugin-adeira/src/rules/__tests__/valid-test-folder.test.js

@@ -5,7 +5,7 @@ const RuleTester = require('eslint').RuleTester;
 const rule = require('../valid-test-folder');
 
 const ruleTester = new RuleTester({
-  parser: require.resolve('@babel/eslint-parser'),
+  parser: require.resolve('hermes-eslint'),
 });
 
 ruleTester.run('valid-test-folder', rule, {

src/eslint-plugin-sx/package.json

@@ -25,8 +25,8 @@
     "@adeira/flow-types-eslint": "0.0.0",
     "@adeira/sx": "^0.29.1",
     "@babel/code-frame": "^7.18.6",
-    "@babel/eslint-parser": "^7.18.2",
     "eslint": "^8.19.0",
+    "hermes-eslint": "^0.9.0",
     "react": "^18.2.0"
   },
   "peerDependencies": {

src/eslint-plugin-sx/src/rules/__tests__/no-unused-stylesheet.test.js

@@ -20,7 +20,7 @@ testFixtures({
 });
 
 const ruleTester = new RuleTester({
-  parser: require.resolve('@babel/eslint-parser'),
+  parser: require.resolve('hermes-eslint'),
 });
 
 // This test makes sure we are reporting correct lines and columns:

src/relay/src/internal/__tests__/helpers.getRequestBody.test.js

@@ -42,8 +42,8 @@ it('returns request body with uploadables', () => {
     },
     { bbb: 222 }, // variables
     {
-      foo: new File(['foo'], 'foo.txt'), // eslint-disable-line no-undef
-      bar: new File(['bar'], 'bar.txt'), // eslint-disable-line no-undef
+      foo: new File(['foo'], 'foo.txt'),
+      bar: new File(['bar'], 'bar.txt'),
     },
   );
 
@@ -67,8 +67,8 @@ it('returns request body with uploadables - persistent queries', () => {
     },
     {}, // variables
     {
-      foo: new File(['foo'], 'foo.txt'), // eslint-disable-line no-undef
-      bar: new File(['bar'], 'bar.txt'), // eslint-disable-line no-undef
+      foo: new File(['foo'], 'foo.txt'),
+      bar: new File(['bar'], 'bar.txt'),
     },
   );